Conventional pulse doppler radar systems radiate a coherent pulse train that, when reflected by a scatterer, returns signals that can provide data including the range (the distance from the antenna) and the range rate (the radial velocity away from the antenna) of the scatterer. A wide range of pulse doppler radar systems have been used in the prior art, with applications including airborne or surface-based antennas, for surveillance, weapons control and tracking, and meteorological observation, among others. In general, pulse doppler radar systems are used where moving targets are desired to be detected amidst an environment replete with clutter, or scatterers other than the desired target.
Due to rapid advances in digital signal processing (DSP) technology, many modern radar systems, including pulse doppler radar systems, digitize the return signals and utilize DSP for target detection and discrimination. DSP technology can improve the performance of a radar system while reducing its cost. Furthermore, the flexibility allowed by DSP systems can improve signal detection by enabling real-time adaptation of the receiver to various conditions.
However, radar detection of slow-moving targets such as walking humans (known in the field as dismounts) is significantly degraded by clutter. Furthermore, even if a dismount were detected, the discrimination of a particular dismount within a crowded environment is a goal rarely if ever achieved within the prior art. Thus, there is a need for a radar system capable of detecting and discriminating a slow-moving target such as a particular walking human in a crowd.